How can I use the MS Trebuchet font in LaTeX, or in this case, tikzposter? I have tried the awnser from How to use the MS Trebuchet font? with this code:
\usepackage[T1]{fontenc} % https://tex.stackexchange.com/questions/33739/how-to-use-the-ms-trebuchet-font
\pdfmapfile{+winfonts.map}
\renewcommand\rmdefault{trebuchet}
But I just get a warning like this:
LaTeX Font Warning: Font shape `T1/trebuchet/m/n' undefined
The formatting does then not work with bold or italic text anymore.

\usepackage{fontspec}just below document class. Then add\setmainfont{MS Trebuchet}just below that. Do not usefontencorrmdefault(already invoked by fontspec). Not sure about the pdfmapfile, but I think it should be omitted. Then compile with lualatex. Command linelualatex yourdocument.texso that you are compiling with utf8 encoding (known as TU within TeX). – rallg Oct 27 '23 at 16:02inputenc, drop that, too, and droptextcomp, if you use that. If you're using other font packages, drop if not compatible. You can keep maths fonts traditional and just change the text fonts tofontspec, which is probably the path of least resistance. – cfr Oct 27 '23 at 17:21Font shapeT1/aer/b/sc' undefined` and the font does not change.edit: now it says:
– KGB91 Oct 27 '23 at 18:00! Fatal Package fontspec Error: The fontspec package requires either XeTeX or(fontspec) LuaTeX.(fontspec)(fontspec) You must change your typesetting engine to,(fontspec) e.g., "xelatex" or "lualatex" instead of(fontspec) "latex" or "pdflatex".Type <return> to continue.... \msg_fatal:nn {fontspec} {cannot-use-pdftex}lualatexnotluatex. If your system does not havelualatex(it is probably a softlink toluahbtex) then create the softlink yourself. – rallg Oct 27 '23 at 18:39Fira Sansinstead of Trebuchet. It is available as a TeX package, and includes a file format that does not reuirefontspecorlualatex. Instructions are in the LaTeX font catalog, at this page: https://tug.org/FontCatalogue/firasans/ – rallg Oct 27 '23 at 18:56